Research from different traditions suggests that attempts at emotion regulation have effects on psychological and physical health, most likely through mechanisms at multiple levels, like the physiological and social. However, little is known about 1) the temporal aspects of emotion regulation, and 2) how an individual's habitual way of regulating emotion interacts with specific, effortful attempts at regulation to impact the success of such attempts. Knowledge of these two areas will inform what strategy may prove most beneficial for an individual at different points in the developing emotional response. This proposal addresses both issues. The main goal of this study is to determine whether physiological measures of affective chronometry will differentiate between the habitual use and voluntary manipulation of two emotion regulation strategies, cognitive reappraisal and expressive suppression, for the down-regulation of negative emotion within a picture perception paradigm. Individuals identified through a self-report measure as habitual reappraisers or habitual suppressors, and controls who do not report relying on either strategy preferentially, will be exposed to emotion-eliciting images under one of three instruction conditions: watching the images, engaging in cognitive reappraisal, or engaging in expressive suppression. Analyses of overall magnitude and temporal aspects of facial electromyography (EMG) and startle reflex modulation, as well as skin conductance response (SCR) magnitude, will be used to examine differences between the habitual and voluntary engagement in these two emotion regulation strategies. The specific questions this study will address are: 1) Will self-reported differences in habitual use of reappraisal and suppression be reflected in physiological measures of affective response and affective chronometry? 2) Will voluntary engagement in reappraisal or suppression be reflected in these same measures? 3) Do habitual emotion regulation strategy and voluntary manipulation interact in their effects on these measures?